Convert a data frame into 1/0s

Question

I have a data frame of 166 people which I would like to convert to a binary matrix. So in the data frame it looks like the following:

I am just wondering what code could I use to convert this to binary ie 1/0s

A = absent
N = no 
Y = yes 

All for votes

Any help would be appreciated !

Answer 1

I've just created some sample data, If I understand what you are looking for correctly -

df <-matrix(sample(c("a","n","y"),166*20, replace = TRUE),166,20)
df[df == "a"]=NA
df[df == "y"]= 1
df[df == "n"] = 0